A laboratory course in invertebrate zoöloy

Preface

In the preparation of this book the author has had in mind the requirements of a class of students who are pursuing a course of laboratory work in Invertebrate Zoology. An effort has been made to direct the work, without, at the same time, actually telling the student all that there is to be learned from the specimen. It is taken for granted that an instructor is present to assist when there is trouble, and to demonstrate many things that written descriptions might only render more confusing.

The animals that have been selected are not always the most typical, but they are generally forms that can easily be secured and preserved.

In the Appendix a few words have been given regarding laboratory methods, etc. It has not been thought advisable to introduce any considerable treatment of the microscope as an optical instrument, nor have the modern iv Preface,

and valuable methods of microscopical research been more than outlined. The former will be found in numerous text-books ; for the latter, it is expected that the student will consult Whitman's *^ Methods of Microscopical Anatomy and Embryology " and Lee's " Microtomists' Vade-Mecum."

Providence, R.I., March, 1892.